One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,10)(8,9)(11,12)(21,22,24,26)(23,25,27,28)(1,2,3,4)(6,9)(10,12)(14,17)(18,20)(23,27)(25,28)(7,11)(10,12)(13,14)(15,18)(16,17)(19,20)(21,22)(23,25)(24,26)(27,28) involution — undirected(5,7)(6,10)(8,11)(9,12)(21,23)(22,25)(24,27)(26,28) involution — undirected(5,6)(7,10)(8,9)(11,12)(13,15,16,19)(14,18,17,20)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.